Solid polymers of perhalogenated polyolefins



United States Patent" 0 some PoLYnmRs on PERHAILOGENATED POLYOLEFINS William T. Miller, Ithaca, N. Y.

No Drawing. Application February 19, 1951, Serial No. 211,790

24 Claims; (Cl. 260---33.8)

This application is a continuation-in-part of my copending applications Serial No. 601,387, filed June 25, 1945, now abandoned; Serial No. 10,912, filed February 25, 1948, now U. S. Patent No. 2,567,956; Serial No. 68,070, filed December 29, 1948; and Serial No. 69,237, filed January 4, 1949, both last now abandoned.

This invention relates to fluorocarbons and their derivatives and more particularly to polymers of polyunsaturated fluoroolefins such as conjugated and non-conjugated diolefins; and to a thermal method useful for producing the polymers as well as compounds containing four carbon atom membered rings.

In this application, the prefix poly modifies the term connected thereto and generally refers to the number of fluorine atoms or double bonds in the molecule and not to a multiple of a monomer unless the term polymer or derivative term is used.

The term fluorocarbon designates a carbon compound in which all of the substituents are fluorine unless otherwise indicated by a modifier. Thus, derivatives may be obtained corresponding to the replacement of fluorine by another group, analogous to hydrocarbon derivatives formed by the replacement of hydrogen in a hydrocarbon. Such a compound may be saturated or unsaturated.

The term perhalogenated with reference to compounds is used in a broad sense. The prefix per is used to indicate that all the hydrogen atoms of the corresponding hydrocarbon or hydrocarbon derivative are of the type indicated by the term following per, unless otherwise indicated. That is, a perhalogenated compound is a compound in which all the hydrogen atoms arereplaced by halogen.

In recent years there has been considerable interest in carbon compounds containing fluorine, particularly in those which contain a relatively large percentage of fluorine and few reactive bonds such as the saturated fluorocarbons, because of their high degree of inertness to may reactive sbstances; and in developing practical and V commercially useful methods of preparing them. However, up to the time of this invention, only a small number of these compounds was known. I have found that the derivatives of the fluorocarbons, in which a minor proportion of the fluorine atoms has been replaced by another halogen or a stable radical and particularly by chlorine, for many purposes possess stability comparable to that of the fluorocarbons and offer attractive economies in view of the frequently lower cost of the substituted group such as chlorine, as compared with fluorine. The

2,729,613 Fatented Jan. 3, 1956 tially hydrogen-free fluorocarbons and their halogen derivatives.

Another object of the invention is to provide novel compounds: including polymers of polyunsaturated perhaloolefines containing fluorine especially the conjugated diolefins, and a method for producing these compounds.

Another object of the invention is to provide polymers of such olefins, ranging in molecular weight from the dimers to multiples of the highest molecular weight and in physical characteristics from liquids of low viscosity and relatively high volatility which can be readily distilled through oils of. medium to high viscosity, solids of waxy consistency and very low volatility (having a vapor pressure less than 0.001 mm. Hg at 25 C.) and up to plastic materials of excellent mechanical strength and fabricating properties.

Another object of the invention is to provide a class of fluoropolymers, individual members of which depending on their molecular weight and chemical structure, are useful as coolants, solvents, plasticizers, lubricants and plastics with novel properties, the members consisting substantially of carbon and fluorine or of carbon, fluorine and chlorine being particularly useful in applications where reactive substances are present.

Another object of the invention is to provide unsaturated fiuoro perhalocarbons of low and of intermediate molecular weight and a practical synthesis for them.

Another object of the invention is to devise a convenient and effective synthesis for the dimers and trimers of fluoro perhalogenated conjugated diolefins, the perfluorocarbons and perfluorochlorocarbons especially aiter further treatment to saturate the unsaturated bonds present with fluorine or chlorine, beinguseful as lubricants where reactive substances are present.

Another object of the invention is to provide an efiec tive method of producing fluoro perhalocyclobutenes and cyclobutanes, particularly those consisting of carbon and fluorine or carbon, fluorine and chlorine.

Another object of the invention is to provide an effective method for producing aliphatic unsaturated fluoro perhalocarbons.

Another object of the invention is to produce saturated fluorocarbons and chlorofluorocarbons.

Another object of the invention is to provide fluorine containing compounds containing condensed rings of which at least one is a cyclobutane ring.

Another object of the invention is to provide fluorine containing compounds containing at least two rings, at least one of which is a cyclobutane ring. 1

Another object of the invention is to provide new solid polymers.

Another object of the invention is to provide new plastic materials.

Another object of the invention is to provide plastic materials whose characteristic chemical and thermal stability render them widely useful in the handling of corrosive materials.

Another object of the invention is to provide substantially completelyfluorine-substituted plastics which are elastic at relatively high and at relatively low temper atures.

Another object of the invention is to provide ther1noplastic materials which have a high degree of thermal group of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms. As one sub-class, the products of this invention are polymers of. fluorine substituted conjugated diolefins of the general formula RO=CC=OR R R R R in which at least one of the R substituents is fluorine and the remaining R substituents are selected from the group of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms. The R substituents may be the same or different. The preferred products of the present invention are polymers made from the olefins that consist of carbon and halogen and especially carbon and fluorine. or carbon, fluorine and chlorine, because of their high degree of chemical stability. These monomers may, however, be substituted for example by a perhalo organic radical or functional group such as an ether group as --OCF3, -OC2F5, -OC3F7, or OCFC12, or a -CN or NO2 group; they are capable of undergoing polymerization without these groups being attacked and the products will be moderately stable. It is also preferred that the polymers be made from diolefins such as perfluorohexadiene-1,5 and especially conjugated diolefins of which hexafluorobutadiene-1,3 is the most preferred. However, the properties of the products may be varied in accordance with the use for which they are intended, by employing a monomer similar to hexafluorobutadiene-1,3 but different in that one or some of the fluorine atoms is replaced by a chlorine atom or by a perfluoroalkyl group such as CF3, --C2F5 or CsFv, or a perchlorofluoroalkyl group such as CClF2, C2Cl2F3, C3Cl3F4, etc.

The polymers of the present invention range in molecular weight from the low molecular weight polymers such as the dimers and trimers, through the polymers of intermediate molecular weight including very viscous oils to waxy solids of low mechanical strength, and up to polymers of very high molecular weight which are useful as plastics. In the formation fo polymers, ring structures are formed which in general are four carbon atom membered rings although it is believed that rings with a higher number of carbon atoms are formed to a lesser extent and that the latter are unsaturated rather than aromatic. As re gards molecular weight, the preferred polymers of this invention are the oils of viscosities corresponding to lubricants, and the solid polymers in the plastics range of molecular weight which are capable of being fabricated into durable articles and used as materials of construction. The term plastic is used herein to denote polymers which have considerable mechanical strength with a tensile strength in excess of 500 pounds per square inch and which may be formed hot.

According to the method of the present invention, useful compounds are made by heating at a temperature in the range of about 90 C. to about 700 C., a compound having at least three base carbon atoms, at least two double bonds between base carbon atoms, and at least one and preferably several fluorine atoms attached to a base carbon atom, and in which the remaining substitutents are selected from the group of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms. It is desirable that the starting material be a diolefin, especially of the conjugated type. Preferably the monomer consists of carbon and halogen and especially of carbon and fluorine or carbon, fluorine and chlorine. The products of the reaction belong to the group of dimers, trimers, polymers of greater molecular weight such as normally liquid and solid polymers, and the fluorine-substituted unsaturated and saturated compounds such as the cyclobutenes and cyclobutanes. The dimers and trimers may contain four carbon atom membered rings, e. g., cyclobutane rings.

The process of this invention may be carried out using a continuous flow system or a batch system. In the continuous flow system, the starting compound is passed through a reaction zone at an elevated temperature with a contact time of not more than a few minutes and preferably of 1 to 100 seconds. With this technique it is advantageous to employ temperatures in the range of above about 300 C. to about 700 C. and preferably about 400 C. to about 650 C. The reaction is suitably carried out at atmospheric pressure but if desired subatmospheric or super-atmospheric pressures may be used.

Pressures of about 16,000 atmospheres may be used. When the monomer is a conjugated diolefin, an important product is the cyclobutene and the reaction equation is the following:

In the above formulas, at least one of the R substituents is fluorine and the remaining R substituents are selected from the group of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms. It will be noted that an intramolecular cyclization takes place, the end carbon atoms becoming joined and the unsaturations at the end carbon atoms being supplanted by an unsaturation between the middle carbon atoms and the R substituents of each carbon atom remaining the same. One useful sub-class of products of the reaction consists of fluorocyclobutenes in which all of the R substituents are halogen selected from the group of fluorine and chlorine; and another useful sub-class of higher molecular weight consists of fluorocyclobutenes consisting of carbon and halogen in which the halogen is selected from the group of fluorine and chlorine and which are substituted by at least one perhaloalkyl radical of up to three carbon atoms. When the monomer. is a non-conjugated diolefin, an important product is a cyclobutane compound and the reaction equation is the followmg:

where n is a whole number less than six and preferably from two to four, and R has the same meaning as above. It is noted that these products are also produced by intramolecular oyclization. These cyclized products thus have at least two condensed rings of which at least one is a cyclobutane ring.

Alternatively a batch system may be used in which the starting compound is heated in a bomb for a period of time of the order of several hours. With this technique it is desirable to employ temperatures in the range of about C. to about 300 C.; with temperatures in the range of about C. to about 200 C. being preferred. it is advantageous to permit the reaction to proceed at antogenous pressures of several atmospheres to obtain higher yields for a given container space, but if desired atmospheric or reduced pressures may be used. In this manner there may be obtained dimers, trimers, polymers of greater molecular weight, cyclobutenes and compounds containing cyclobutane rings. Distillation is a convenient method of separating the reaction products. Conditions may be regulated so as to control the principal product such as to obtain the dimer as the principal product or so as to yield a considerable quantity of trimer and higher molecular weight material. Maintaining the monomer in excess by choosing conditions which result in only partial reaction leads, largely to the formation of the dimer.

On the other hand, if the reaction is carried to completion, larger quantities of trimer are formed and in general its formation may be further promoted by maintain- This latter procedure also favors the formation of increased quantities of ma.- terial of higher molecular weight than the trimer.

Temperatures substantially in excess of the minimum temperature for bringing about reaction generally favor the progressive polymerization of the dimer and trimer to higher molecular weight products.

The thermal reaction of this invention is characterized by the fact that it can be effected in the temperature range of 90 C. to 700 C. in the absence of catalysts and without the use of very high pressures. However, other substances may be present if desired. Anti-oxidants such as catechol may be used for the purpose of impeding the formation of long polymer chains, but are not essential. Catalysts and promoters may be used that are active in the temperature range set forth without departing from the scope of this invention.

The term polymerization promoter designates a substance whose function is the same as that of a catalyst in that it increases the rate of reaction, but differs from a catalyst in that it or fragments of it may be found in minor percentages in the polymer, particularly at the ends of the polymer chains; in the process it is consumed.

Generally speaking, when polymerization is carried out in the presence of a free radical-chain forming type promoter such as an organic peroxide, e. g., benzoyl peroxide, there is a tendency for longer chains to be formed with the production of a substantial yield of solid polymers. Promoters of this type include acetyl peroxide, chloroacetyl peroxide, difluoromonochloroacetyl peroxide, trifluoroacetyl peroxide, trichloroacetyl peroxide and oxygen. When an organic peroxide is used, the temperature selected should be such that it decomposes at a regulated rate. Ionic type catalysts such as aluminum chloride or stannic chloride or boron trifluoride or their complexes with organic compounds such as others may also be used to advantage in specific cases for the production of polymers by the method of this invention.

If desired, the reaction may be carried out in the pres ence of water with or without added emulsifiers. It may be carried out in the presence of dyes, pigments, plasticizers, fillers, natural resins, graphite or other modifiers.

Other methods useful in preparing solid polymers of hexailuorobutadiene-LB are described in detail in the copending applications referred to above and will be described herein but briefly.

When hexafluorobutadiene-l,3 is polymerized at pressures of the order of 1,000 atmospheres and less, it is desirable to use a small concentration of a promoter. In general, the amount used should not be in excess of about three percent by weight based on the monomer and preferably less than one percent. The temperature of this polymerization may be less than 70 :C. The molecular weight of the polymer is increased at higher pressures and at lower concentrations of promoter. The products so ob tained may range in properties from a heavy liquid to a relatively brittle solid and up to plastics. A polymer having the higher molecular weight characteristic of a plastic may be produced at these pressures by properly choosing the polymerization conditions. The mechanical characteristics of the plastic may be altered by use of a plasticizer such as a lower molecular weight liquid polymer or other compatible relatively low molecular weight material.

A rubbery thermoplastic polymer of very high molecular weight may be prepared by polymerizing hexafluorobutadiene-l,3 at extreme pressures in. the range of 10,000 to 20,000 kgs./cm. Under this high pressure a good yield is obtained generally in less than 24 hours at temperatures of less than 70 C.

. used to seal the piston.

tha rubber since it is substantially co pl t ly b b tuted with fluorine and therefore contains substantially no carbon-hydrogen bonds. The corrosion resistance is, however, somewhat less than that of a saturated fluorocarbon such as tetrafluoroethylene polymer since the hexafluorobutadiene polymer retains double bonds in its mole cules. However, the corrosion resistance of the latter may be made substantially equal to that of polytetrafluoroethylene by treating the polymer with a fluorinating agent. Treatment of the rubbery plastic polymer with elementary fluorine acts in a manner similar to the vulcanization of rubber and hardcns the material. In addition, the softening temperature of the polymer is in general increased by the fluorination. Alternatively, it may be treated with chlorine or mixtures of chlorine and fluorine or chlorine trifluoride to increase its corrosion resistance. In this instance the polymer retains its flexibility.

In the examples in which preparations of polymer were carried out at pressures in excess of l0,000 kgs./em. these were accomplished in equipment described in Physics of High Pressure by P. W. Bridgman, published by the MacMillan Company in New York in 1931. The steel pressure cylinder employed had a useful volume of ap proximately 8 to 15 cos. and chloroprene gaskets were When a solid peroxide was in cluded in the polymerization mixture, the pressure cylinder was rotated in a lathe to ensure complete mixing before application of high pressure.

EXAMPLE 1 Hexafiuorobutadiene-1,3 was passed through a hot tube. The tube was surrounded by an oven and was formed with a central opening for a thermocouple. It was connected at one end to a source of olefin supply and at the other end to a receiver maintained at room temperature connected in turn to a receiver cooled by Dry Ice. About gs. of hexatiuorobutadiene-l,3 was passed through the tube at a temperature of 400 C. with a heat contact time of the order of seconds. At 400 C. reaction was rapid. The crude products were distilled and 45.8 gs. of a distillate having a boiling range of 5 C. to 10 C. was obtained. This distillate was allowed to stand overnight in a container cooled by Dry Ice and a considerable amount formed a crystalline white solid. Hexafluorobutadiene-l,3 does not crystallize at Dry Ice temperature. About 3 gs. of liquid consisting mostly of hexafluorobutadiene lj was poured off. The remaining crystalline solid was allowed to melt and then was distilled. About 22.7 gs. of a material consisting largely of hexafluorocyclobutene and hav ing a boiling range of 4.5 C. to 5.5 C. was obtained.

A sample of this material weighing about 20 g was sealed in a tube with an equal volume of liquid chlorine and the tube was exposed to direct sunlight at 45 C. for about 12 hours. The tube was then opened, volatile matter was permitted to escape at room temperature and the residue was distilled. About 13 gs. of a material consisting essentially of ClFsClz (dichlorohexafluoro cyclobutane) molecular weight, 231.6 (theoretical molecular weight of CFGClZ, 232.9) was obtained. This material was tested with a solution of potassium permanganate in acetone which is a sensitive reagent for detecting olefins consisting of carbon, fluorine and chlorine, which are readily oxidized thereby, and was evidently saturated.

EXAMPLE 2 l-Iexafiuorobutadiene-LS was passed through a Pyrex tube at 500 C. to 530 C. A solid white product consisting essentially of hexafluorocyclobutene was obtained in a dry-ice cooled trap.

EXAMPLE 3 l ,4-dichloropertluorobutadiene-l ,3

(CFCl=CF-CF=.=CFC11) was passed through a hot nickel tube at approximately 400 C. with a calculated contact timeof 14 seconds. to

arrears- 7 yield a condensate with reduced index of refraction (from n 1.4047 for the butadiene to n 1.3965 for product) from which a substantial fraction of material was separated boiling lower than the starting butadiene and consisting essentially of 3,4-dichloroperfluorocyclobutene having a boiling range of 64 to 70 C. and boiling largely from 66.5 to 68 C., uncorrected.

In another similar preparation carried out at a maximum temperature of 400 C. with a calculated contact time of 60 seconds, a 28% yield of a fraction consisting essentially of cyclobutene boiling from 63.5 to 66 C. was obtained. A carefully measured boiling point in- 1 dicated that the cyclobutene boils at 64.5 C. at 735 mm. Hg.

2,3-dichloroperfluorocyclobuteue may be used in syntheses to produce other new and useful fluorocarbons. Thus it may be caused to react with chlorine in the pres- 2O ence of light to add chlorine and saturate the double bond:

The product OFCI-CFCI CFOl- F01 1,2,3,4-tetrachloroperfiuorocyclobutane is characterized by a melting point of 40 c. 30

. EXAMPLE 4 2,3-dichloroperfluorobutadiene-l,3

' (CFz=CCl-CCl=CFz) was heated at about 176 C. for 89 hours. An appreciable yield of cyclized product was recovered, 1,2-dichloro- B. 'P. 66-68 C. Excess butadiene was separated from the cyclobutene by chlorination of the mixture followed by distillation to recover the butene in the form of its chlorine addition product l,l,2,2-tetrachloroperfluorocyclobutane.

O F:C Fz-C Girl 01 M. P. 83.2-83.5 C. 1,Z-dichloroperfluorocyclobutene may be recovered from the tetrachloride by dechlorination with zinc in a solvent, suitably at the reflux temperature of the solvent at atmospheric pressure.

The following analogous reactions may also be carried out under similar conditions: 5 5

O A till -o F C F -'C ClC F: F

A C F2O F CFC1=OFCF=CF3 l 5] C F Ol F The following reactions may also be carried out under similar conditions:

"Products substituted by other radicals such as, for ex- 15 ample, --C3F7, C2F5, -CF2Cl and --CFCla may similarly be prepared by the intramolecular cyclization of an appropriate compound. These reactions illustrate the heat treatment of conjugated diolefins consisting of carbon and halogen selected from the group of fluorine and chlorine, which are substituted by at least one perhaloalkyl radical of up to three carbon atoms and by at least one fluorine atom, to produce the corresponding fiuorocyclobutenes.

Diene compounds useful for this method are conveniently prepared by dechlorination of the corresponding l,2,3,4-tetrachlorobutane by means of zinc in the presence of a lower aliphatic alcohol, as shown by the following reactions:

Further details of these reactions are given in my c0- pending application Serial Number 173,689 (48), filed July 13, 1950.

The present invention provides a convenient and effective synthesis for a number of useful fiuoro perhalocarbons containing a' four carbon atom membered ring. This method is adapted to rapid, continuous operation and is a one-step process which has the advantage of avoiding the separation of purification of intermediate reaction products. The rearrangement can beretfected by means of heat alone without the addition of catalysts or other aids to reaction so that the problem of distributing such substances in the starting material is avoided. This method has certain advantages over the process of preparing fluorocyclobutenes which involves the dimerization of a suitable fluoroethylene to produce a polyfiuorocyclobutane derivative of a halogen other than fluorine, followed by removal of halogen to produce the cyclobutene. Thus, for example, trifluoromonochloroethylene, CF2=CFCL may be heated at a temperature in the range of C. to 500 C. under super-atmospheric pressure to yield dichlorohexafiuorocyclobutane,

The latter compound is then dechlorinated with zinc in the presence of ethanol at the reflux temperature of ethanol to give hexafiuorocyclobutene,

By means of the present method, however, certain compounds can be prepared which cannot be prepared by the two-step process. For example,

CFCl-OF I ("JFCl-HTF can be made by cyclization but not from CFCI CFCI by dimerization followed by dechlorination.

By means of this process fluoro perhalocyclobutenes are obtained, in good yield, which are unsaturated and are useful as monomers in polymerization reactions. They are also useful in other syntheses. For example, they may be caused to react with fluorine or chlorine to produce saturated compounds which are useful for various applications, such as for heat exchange liquids in connection with processes in which corrosive substances are used. They may be oxidized to dibasic acids which are useful for further synthesis through the acid functional groups. a Y

EXAMPLE Perfluorohe'xadiene 1,5, CF2:CFCF2CFzCF=CF2, B. P. 60 C; was passed through a hot tube at approximately 450 C. with a contact time of from 30 to 90 seconds. A substantial conversion to lower boiling material occurred. This product, B. P. 42.5-43.0" C., M. P. 41 C., was separated by careful fractionation from unchanged starting material. Unchan'ged diene may also be removed by chlorination to yield its tetrachloride, CFiClCFClCFzCFzCFClCFzCl which is readily' separated by simple fractional distillation from the cyclized product (perfluorobicyclohexane) The product was saturated to an acetone solution of potassium permanganate and to bromine incarbon tetrachloride solution in the presence of strong light. The molecular weight found was 260 and the calculated molecular weight for CsFio is 262. Its structure was indicated as Fr 'F- F: The above experiment is an example of an intramolecular reaction using a preferred subclass of the non-conjugated dienes which have the formula CFX=CX(CR2)11.CX=CFX where n is a whole number less than 6 and preferably 2 to 4, X is either fluorine or chlorine and R is chosen from fluorine,. chlorine or a saturated grouping fully substituted thereby. In this case a saturated fluorocarbon or chlorofluorocarbon is obtained directly in a one-step process in contrast to the corresponding reaction of a conjugated butadiene-l,3 which yields a butene by intramolecular cyclization. The saturated fluorocarbons and chlorofluorocarbons produced by this process are directly useful as heat transfer media, stable solvents, and the like but ingeneral: are not as useful as chemical intermediates as the cyclobutenes obtained from the conjugated butadienes due to the greater reactivity of the latter.

Other examples are illustrated below:

1.0 The preparation of pejrfiuorohex' acliene-1 ,5 is disclosed in my copen ding application Serial Number 173,689 (48), filed July 13, 1950.

EXAMPLE 6 Hexafluorobutadiene-1,3, obtained by the dechlorination of l,2,3,4-tetrachloroperfluorobutane with zinc in the presence of absolute ethyl alcohol, was purified by mixing with P205 and distilling-.- Twosteel bombs were each charged with a quantity of the' diene compound under conditions to exclude oXygenand-wer'e thenheatecl at 180 C; :12 C. for 15 hours. The products were separated by distillation and several fractions were obtained including a low-boiling fraction which condensed, partially as a solid, in a Dry lce trap and consistedlargely of hexafiuorocyclobutene; a fraction boiling frorri 96 to 100 C. containing a product CsF12; a fraction boiling from 62 to 68 C. at 10 mm. Hg containing a product C12F1e; and a higher boiling residuei The Dry Ice trap material was reacted with chlorine in the presence of ultra violet light and the products were distilled to yield F F CC-Cl B. P. -61 C. (uncorrected), obtained by the addition of two atoms of chlorineto and obtained by the addition of four atoms of chlorine to un The results of the runs reacted CFz=CF-CF CF2. aresummarized in Table I.

Table 1' Run No I II Weight starting 04h. "gs. 350 390- Weight recovered material 346 382' Percentof starting material reaete 97 97' Perfluoroeyclobutene; percent of reac d materia 13 13 Perfluorobutadiene dimer, CsFiz, B. P. 96400; permm. Hg; percent of reacted material 29 32 Residue B. P. above at 10 mm. Hg; percent" of reacted material 4 4 The dimers andtrimers are believed toexist' in several isomeric forms. This is borne out by the factthat the raw fractions have an extended boiling range instead of a sharp boiling point and by the isolation of individual isomers from the products. For example, fromFraction II of this experiment there may be recovered 1,2-divinyl perfluorocyclobutane,

1 1 EXAMPLE 7 An experiment wascarried out under conditions similar to those in Example 6 except that the bombs were maintained at 160 C. for 5 hours. The results are summarized in Table II.

Table II Run N I II Weight starting OlFs .gs 323 327 Weight recovered material gs 321 324 Perfluorobutadiene recovered 201. 0 206. 2 Percent of starting material reacted"... 37. 8 36. 9 Perfluorocyclobutene formed .gs- 6. 6 6. 7 Perfluoroeyclobutene; percent of reacted material 5. 4 5.6 03F, perfiuorobutadiene dimer, B. P. 9610U 0.;

percent of reacted material 85.8 85.0 Perfluorobutadiene trimer, B. P. 165180 0.; percent of reacted material 3. 8 3. 2

One-half gram of finely ground catechol was placed in a steel bomb. The bomb was thoroughly flushed with dry nitrogen and 217 grams of hexafluorobutadiene-l,3 which had been distilled through calcium chloride was added. The mixture was heated at about 130 C. for about 30 hours. The bomb was heated in an oil bath up to 75 C. and 32.5 gs. of low boiling material distilled and condensed in a Dry ice trap as a milky liquid. The cloudiness indicated the presence of a crystalline product, hexafluorocyclobutene. 181.6 grams of liquid was poured out of the bomb and separated into fractions by distillation. Distillation yielded 103.8 gs. of a product consisting essentially of CsFiz, B. P. 55-56 C. at 150 mm. Hg; 48.3 gs. of a product consisting essentially of CIZFIB, B. P. 6566 C. at 10 mm. Hg; and a higher boiling residue containing higher polymers of 16 and 20 carbon atoms.

EXAMPLE 9 One-half gram of catechol, 15.6 gs. of heXafluorobutadiene-1,3 and 32.1 gs. of its dimer, C8F12, were placed in a tube under oxygen'excluding conditions. The tube was maintained at 95 C. to 100 C. for 23 hours and then at 150 C. to 160 C. for 41 hours. The products were separated by distillation to yield 2.3 gs. of a low boiling fraction, CrFs; 30.6 gs. of a fraction boiling largely from 98 C. to 102 C. consisting essentially of CaFiz; 7.4 gs. of a fraction consisting essentially of C12F1s, and about 8 gs. of residue. On further distillation of the residue it yielded catechol and a fraction boiling at about 265 C. to 270 C. containing C1sF24.

EXAMPLE 10 About 355 gs. of hexafluorobutadiene-L3 was heated in a bomb at 9496 C. for about 43 hours. A pressure of about 200 pounds per square inch developed in the bomb during heating. The reaction products were distilled. After distilling 281 gs. of material volatile at 60 C. which condensed in a Dry Ice trap, 72 gs. of products remained. About 55 gs. of the latter was separated by fractional distillation in a C02 atmosphere and yielded 36 gs. of a fraction boiling largely from 98.5100 C. in addition to somelower and some higher boiling material. This fraction was refractionated to yield a portion boiling largely at 98.8 C., average molecular weight 12 325, and another portion boiling largely at 100.0 C., average molecular weight 321 (molecular weight CaF12, 324), thus indicating the presence of isomers.

EXAMPLE 11 11.7 grams of C12F1s, prepared by the thermal treatment of hexafluorobutadiene-l,3 at 150 C. in an atmosphere of CO2 and in the presence of catechol, was sealed in a Pyrex tube and heated at about 300 C. for 64 hours. 5.3 grams of polymer, mostly solid, was obtained which did not distill with a bath temperature of 320 C. at 1.5 mm. Hg.

EXAMPLE 12 1.7 grams of C8F12 was heated in a sealed glass tube at 195 C. to 205 C. for 65 hours. After drying the prod ucts at C. for 4 hours, 0.5 g. of a solid, perfiuoro higher polymer was obtained. It was substantially insoluble in ether, 95% alcohol, acetone, C4ClaF-2 or C4Cl4Fs. On being heated in a metal bath, it was stable at temperatures below 250 C.

The starting material, hexafiuorobutadienel,3 dimer, CBFIZ, contains the isomer OFz-OF-OF=OF2 V CFT FC F=C F2 Hence this example illustrates the polymerization of a polyolefinic non-conjugated fiuoro perhalocarbon.

EXAMPLE 13 Perfluorohexadiene-1,5,

CF2=CFCF2CF2CF=CF2, B. P. 60 C., was placed in a steel pressure bomb in a nitrogen atmosphere. The bomb was heated to 200i5 C. for 48 hours in a tubular electric oven. The following products were isolated: CeFio, recovered starting material, CF2=CFCF2CF2CF=CF2, B. P. 60 C.; CeFm, saturated isomer,

0 FzC F IJ Fr Fr- FC F 2 B. P. ca. 43 C., C12F2o, dimer, B. P. 168-175 C.; CraFao, trimer, B. P. 128138 C. at 10 mm. Hg; (C6F10)n, higher polymers, B. P. C. at 10 mm. Hg. The structures are shown below:

dimer OFzCF-GFr-OFa-CF=CF2 A CF2('i1F-OFzCF2CF-OF| CF2 F-CF:--OF2CF=OF7 (iFq-CFQFz-CF: F""CFQ (unsaturated) (saturated) trimer C Fz-C FC Fr-C F2-C F=C F2 F2 F-C Fz-C Fr-C F=C F:

O Fa=O F-C Fa-O Fa-O F- F: tetramer C Fz-C F-G FaC Fz-C F=C F2 0 F2C F-O Fz-O FzO F-C F2 0 Fz-O F-C F2C Fa F- F:

FflC F-O Ffl-O Fz-C F=C F2 Other structures are also formed which involve transfer of fluorine such as CF2=O F-O F2-C F-o F=C F:

C F2=O F 0 F20 Fz- FO Fa but in general not as major products.

EXAMPLE 14 A 5 g. sample of 2,3-dichloroperfluorobutadiene-l,3,

. CF2=CCl-CCl=CF2, boiling at 67--70 C., was heated in a glass tube at C. for 44 hours. The reaction products were distilled and 2 gs. of viscous, oily polymer boiling above C. was recovered.-

The starting material 2,3-dichlorotetrafiuorobutadiene- 1,3 is further characterized by its reaction with bromine to yield a dibromide under the following conditions. Bromine, 28.7 g. was added to 35 gs. of

in a glass tube and the tube sealed after cooling in a Dry Ice bath. The above quantities represent equimolecular amounts. The tube was allowed to warm' gradually in diffuse light. At about C. a vigorous reaction occurred with heat evolution. This was controlled by periodic cooling and: exclusion of light. 1 Finally, after the vigorous reaction was over, the. bomb was irradiated at room temperature with a 1 00 watt Mazda lamp with occasional shaking until the. bromine was absorbed as evidenced by color change. The tube was cooled, opened and the contents distilled to yield: 61.0 gs., B. P. 100.0-104.5 C. at 100 mm. Hg and 1.8 g. residue. The former material was recrystallized from methyl alcohol with Dry Ice cooling and redistilledto yield a center cut of 26.6 gsp, B. P. 103.6-1037 C. at 100mm. Hg; M. P. 6.6 to 6.2 C.; n 1.4710; d4 2.1531. This compound was very resistant to furtherbromination. It was assigned the structure CFzBrCCl=CClCF2Br on the basis of bromine content and failure to brominate further since the other possible isomer CF2=CCl--CClBr--CF2Br would be expected to brominate further. At room temperature it.did not react with 10% sodium iodide during one hour. However, reaction occurred on standing over night. Similar results were obtained with 1N NaCN in methyl alcohol.

EXAMPLE 1 In a nitrogen atmosphere, 135.2 gs. of 2,3-dichlorotetrafluorobutadiene-l,3 was placed in a steel bomb which was fitted with a steel valve. The valve was closed and the bomb heated in a vertical electric oven equipped with a thermoregulator, at about 170 C. for 44 hours. The temperature was determined by a Chromel Alumel thermocouple attached to the bomb. After cooling to 0 C. the reaction product was transferred to a 125 cc. distilling flask. Distillation at 739mm. Hg through a 1.4 x 30 cm. column packed with 4;" glass helices yielded: (1) 77.2 gs., B. P. 66.2-66.7 C. (boiling largely at 665 C.); and (2) 54.0 gs. still residue. Redistillation of (2) yielded (3) 10.7 gs., B. P. 67 C. at 740 mm. Hg to 50 C. at 200 mm; (4) 40.7 gs., B. P. 144 -151 C. at 200 mm; and (5) 1.7 g. higher B. P. residue.

Fractions (1) and (3) consisted of a mixture of which compounds cannot be readily separated by dis.- tillation. This was shown by chlorination followed by separation of the dichloride of the cyclobutene from the tetrachloride of the butadiene. For example, by chlorination of a 20.11 g; sample ofifraction. (1) and separation of the products an approximate composition of 23% cyclobutene and 77% butadiener was established.

After separating a 19.4 g. sample of fraction (4) for chlorination the remainder was filtered at 0 C. and 5 gs. solid material separated. Recrystallization from methyl alcohol yielded 2 gs. White. crystalline solid which sublined at about which sublimed at about 154 C. without melting, melted in a sealed tube at 251.8252.0 C. and was saturated to potassium permanganate dissolved in acetone. Calculatedfor CsFsCh: Cl, 36.4%; F, 39.0%; mol. wt., 390. Found: Cl, 36.4, 36.2%; F, 38.4, 38.5%; mol. wt., 388. and. the method of preparation this compound was assigned the. followingstructure and is named tricyclotetrachlorooctafluorooctane Distillation, of the. liquid filtrate obtained from fraction (4). above: at 100. mm. Hg through a column with a On the basis of. the above observations packed section 1.4 x 30 cm. yielded: (6) 1.9 g., B. P. 1'02-114 C. at mm. Hg (solid at room temperature); (7) 1.4 g., B. P. l14-13 1 C. at 100 mm. Hg (solidliquid mixture at room temperature); (8) 11.8 g., B. P. 13l-137 C. at 100 mm. Hg (liquid at room temperature); (9) 2.5 g. liquid residue. Fraction (8) was unsaturated t'o potassium permanganate in acetone and absorbed bromine in carbon tetrachloride solution with illumination by a 100 watt incandescent lamp. Its physical properties were: formed a glass at approximately 65 C.; 11 1.4373; d4 1.7889.

The unsaturated dimer of 2,3diehlorotetrafluorobutadiene-1,3 was shown to consist of more than one isomer by chlorination. For example, the 19.4 g. sample of fraction" (4) indicated above was sealed in a thick walled glass bomb with 20g. of chlorine and irradiated for 9 days. The products were separated first by simple distillation at 50 and 20 mm. Hg and then by fractional distillation through a short packed column. The following materials were obtained.

Additional tricyclotetra'chlorooctafluorooctane was separated as a lower boiling fraction to which chlorine did not add on.

A dichloro addition product of the dimer of 2',3-dichlorotet'rafluorobutadiene-1,3, a hexachlorooctafluorooctene,

CsClsFs, B. P. 126-l30 C. at 20 mm. Hg, formed a glass at approximately -50 C.- and had these properties: n 1.4536, calculated for CsClsFa, Cl, 45.4%; found, C1, 4518', 45.9%. The product was unsaturated to potasslum permanganate dissolved in acetone. It yielded a white precipitate with 2N CHsONa solution in CHaOH and yielded a precipitate with 10% Mai. These observations indicated the structure 0 F2C=O o1-o CIFQ corresponding to the dimer structure 0 Fz-O=CCl-C 011M CF: (ll-C C1=C F2 before chlorination.

An intermediate fraction corresponding to a tetrachloride of the dimer of 2,3-dichlorotetrafiuorobutadiene l,3, CsClaFs, was separated, of B. P. approximately 132 C. at 3. mm. Hg. Its structure is believed to be corresponding to an original dimer structure of C Fz-C CIO 01:0 F2

uct. The following structure was assigned to this portion of the dimer product C Ft CIC Fa-C Cl=C (ll-Cl Fn-C O Cl=C F2 A. small yieldof trimer or higher polymers of 2,4-dichlorotetrafluorobutadiene was formed at C.

The approximate composition of the reaction mixture obtained by heating 2,3-dichlorotetrafluorobutadiene lfi' at 170 C. as estimated from the boiling points and alcohol 15 weights of distillation fractions is summarized in Table III.

Table III Weight recovered CF2=CCl-CC1:CF2 gs 67.6 Percent of starting material reacted 50 1,Z-dichlorotetrafluorocyclobutene-1; percent of reacted material 30 2,3-dichlorotetrafluorobutadiene-1,3 dimer; percent of reacted material:

Saturated dimer 22 Unsaturated dimer 42 EXAMPLE 16 0.13 gram benzoyl peroxide was added to 12.3 gs. of 2,3-dichlorotetrafiuorobutadiene-1,3 in a small pressure bomb. The bomb was sealed and heated for 44 hours at about 85 C. (Under these conditions in the absence of added peroxide no appreciable thermal polymerization of the butadiene occurs.) After cooling the bomb it was opened and the contents distilled to yield: 10.9 gs.;recovered butadiene fraction, B. P. 6769 C. and 1.0 g. residue remaining after heating to 160 C. The residue was a viscous yellow oil polymer with an index of refraction of 1.520 at 20 C. as compared with an 11 of 1.3838 for the monomeric butadiene.

EXAMPLE '17 1930 grams of hexafluorobutadiene-1,3 was placed in a pressure container and heated at 150 C. for 43 hours. After permitting 150 gs. of volatile material to distill out of the bomb, by heating up to 60 C. in a water bath, the remainder was fractionally distilled. 1026 grams of the dimer, CsFrz, was obtained. The residue from this dis tillation was distilled under vacuum and yielded 190 gs. of the trimer, C12F1s.

Hexafluorobutadiene-l,3 was heated under various conditions as set forth in the following table of examples. The products noted were obtained by distillation after removal of volatile material. In each example, a substantial amount of dimer was obtained.

heated on a hot plate to remove the acetone. The solid remaining after this treatment was washed with acetone. There were separated a solid, white powder which was a 60% of the original solid obtained and a tacky, gummy material which was 40% of the product of polymerization.

The solid powder melted at 125 C.

EXAMPLE 26 One hundred gs. of hexafluorobutadiene-1,3 was polymerized at 85 C. for 63 hours in the presence of 10 g s. of benzoyl peroxide. The unreacted monomer was allowed to evaporate from the bomb and there remained 47.8 gs. of a white, tacky, wax-like material.

EXAMPLE 27 A CHCls-insoluble hexafiuorobutadiene-1,3 polymer was prepared by heating the monomer with 4% by weight of benzoyl peroxide at 8085 C. for about 100 hours,

removing by distillation the material volatile up to 100 C. at 0.5 mm. Hg, and extracting the residue with CHCls. The CHClz-insoluble polymer was entirely melted at 120 C. A gram sample was mixed with CoFs and 140 gs. of a saturated fluorocarbon lubricating oil, B. P. 177- 25. 187 C. at 10 mm. Hg, as a solvent. The mixture was heated over a period of 24 hours, the temperature being raised gradually to 260 C. The cobaltic fluoride was added in portions at intervals during heating, 129 gs. being used in all. At the end of the reaction, the mixture 30 of solid polymer and lubricating oil was washed first with 5 polymer. There remained a white polymer which melted from 190 C. to 200 C. and which was soft enough to be easily worked at 160 C. The polymer did not decolorize a solution of potassium permanganate in acetone which oxidizes unsaturated fluoroearbons, and was apparently saturated. A saturated oil polymer of the di- Wt. Other Wt. Example Reagent Temp. Time Reagents 04F Products No. Added Adgged, gs 0. hrs.

SbClr 5 54 125 44 10.8 gs. fraction B. P. 82-98 0. 811014 5 52 125 44 5.6 gs. fraction B. 1?. 94-945 0. and

14.8 gs. residue. None 52 125 44 11.8 gs. fraction B. P. 9798.5 O. and

5.7 gs. residue. H250 1.5 49 125 44 23.7 gs. fractiou'B. 1?. 97-9813" 0. and

3.9 gs. residue. 22 AgNO: 2 47 125 44 16.2 gs. fraction B. P. 9798.5 G. and

1.2 gs. residue. 23 Na Oz 1 51 125 44 12.4 gs. fraction B. P. 9798 O. and a solid residue.

The following examples illustrate the production of 55 ene compound was recovered by vacuum distillation from solid polymers of fiuoro perhalogenated polyolefins, which in some instances are of moderate molecular weight and in other instances of high molecular weight with utility as resilient, rubbery plastics.

EXAMPLE 24 EXAMPLE 25 Approximately 99 gs. of hexafluorobutadiene-1,3 was polymerized for 7 days at 70 C. in the presence of 0.5 g. of benzoyl peroxide. From this reaction 5 gs; of a white, slightly gummy solid was obtained which had little mechanical strength. The product was ground under 7 acetone with a mortar and pestle and thereafter was the Freon solution.

EXAMPLE 28 2.4 grams perfluorobutadiene-1,3 and 0.2 g. benzoyl peroxide were heated together under pressure in a water bath at about 100 C. for 54 hours. Upon removal of volatile material and purification of the polymer, 0.5 g. of an oily solid was obtained.

EXAMPLE 29 Polymerization of 2.3 gs. hexafluorobutadiene-l,3

with 0.2 benzoyl peroxide for 54 hours with a 200 watt lamp illumination yielded after removal of volatile material, a small amount of product having a boiling point below 210 C. and 0.9 g. of residue boiling above 210 C.

EXAMPLE 30.

Under a pressure of 16,000 kg ./cm. approximately 16 ccs. of hexafluorobutadiene-l,3 was polymerized for 18 hours at 63 C. The solid polymer was heated on an iron plate up to a temperature of about 275 C. at

whichapoint it could zbeleasily spread by pressing manually with a spatula. The polymer was very rubbery at about 300 C. at which point there was novisible tendency to liquefy, although the sample retained only slight mechan ical strength.

EXAMPLE 31 Fifteen cos. of hexafluorobutadiene-1,3 was polymer ized for 24 hours at a temperature of 65 C. in the presence of 0.1% benzoyl peroxide by weight based on the monomer. The applied pressure was approximately 15,000 kg./cm. The solid product obtained was heated on an iron plate. At 300 C. the plastic was very resilient with only slight mechanical strength.

In the preferred method of molding, the solid polymer is placed in a positive mold maintained at about 275" C. A pressure .is applied to 'the mold just suflicient to cause a slight .extrusion of the polymer around the joint of the mold. The polymer temperature should be between 250 and 27:5 C. .during .the molding and the pressure should .z'hc applied throughout .the molding cycle.

The molded polymer is translucent, hexib'le :and elastic.

.The properties :described hereinafter are those of the polymer which is produced at pressures .of 10,000 to 20,000 kg./cm. molding is notable especially at elevated temperatures. For example, after the thickness of a molded disk thick and 1% in diameter was reduced about 40% under a load of 2,000 pounds, the plug returned almost immediately to substantially its original shape upon removal of the load. The molded polymer is translucent andsuificiently flexible :to permit sharp bends substantially withoutpermanentset.

The tensilestrcngth of themolded polymer is in excess of 1,300 pounds per square inch and it may be stretched to tan elongation ofmore than 200% with at least 50% recovery from the stretched length in 24 ,hours at room The polymer is substantiallynot cross-linked.

At elevated temperatures the polymer is especially elastic. For example, undera pressure of .about'3-3 pounds per square inch on a disk in diameter, cut from a sheet molded under pressure as described above, the disk of the polymer compressed froma thicknessof .170 mils to .5.0.mils in 15 secondsat 225 ,C. At the end of ,10

minutes .the thickness was reduced to about 40 .mils un- .der the same conditions. However, on releasing the pressure, the sample immediately regainedapproximately its original shape. It was noted that on heating from room temperature to. 225C. the above-, uentioned disk expanded considerably in thickness and the diameter was reduced. .Such an expansion under heating is particularly valuable in gaskets. Thus, when a vessel is gasketed at room temperature and the vessel heated to an elevated temperature, the gasket seal is improved by the expans'ion of the gasket material.

At 125* C. the thickness of the central portion of a molded .disk about A" in thickness was reduced about 9.3% with 84% recovery. ,In a repeated compression of .the same sample the thickness was reduced 92% and recovered to within 97% of its value before compression.

The plastic hexafiuorobutadiene polymer may be plasticized to yield valuable products. The polymer produced at pressures in excess of 10,000 kg./cm. after plasticizing may .be molded relatively easilyin apositive-typemold or simply hot-pressed, provided the pressure is :maintained throughout the moldingoperation. The preferred '.plas ticizers are liquid .alkyl compounds which are .com-

The elasticity of this polymer after a pletclu halogen substituted and contain a considerable amount of fluorine, for example, low molecular weight liquid hexafluorobutadiene polymer saturated with fluorine by treatment with a ,fiuorinating agent, completely fluorine-substituted lubricating oil or low molecular weight liquid polymers of CzFsCl. The last of these liquids is disclosed in my co-pending application, Serial Number 743,455 filed April 23, 1947. It is preferred to use between 10 and 50% plasticizer in the final product based on the weight of the polymer. Other useful plasticizers are halogenated ethers such as and partially halogenated hydrocarbons as CFzClCHzCHzCHzCHzCFzCl, CClsCCHflsCH and CF3(CH2)11CF3 where n is higher than 4.

A sample of the high molecular weight solid hexafluorobutadiene polymer prepared at .a. pressure ,in .excess of 10,000kgs./cm. was plasticized by heating it ,fpr 20 minutes with a low molecular weight liquid hexafiuorobutadiene-l,3 polymer which had been saturated with fluorine by treatment with cobalt trifluoride. The plasticizer was soluble in Freon 113, CzClsFs. The plasticized polymer was soft and could be pressed hot to form a film. Another sample was treated with the same low molecular weight polymcrin approximately a 1:1 weight ratio. The plasticized high molecular weight polymer was pressed at 1-'/O C. to ,form a sheet and thereafter was washed with Freon 113 to remove the excess plasti- ,cizer. After Washing, the solid polymer was press fitted cold to yield a translucent rubbery valveseat. With this material a vacuum-tight seal is easily obtained at the valve seat with a small applied force.

Still another sample of the same material was treated with fiuorinated lubricating oil (boiling point 167 to 177 -C. at 10 mms. Hg.) dissolvedin Freon 113. The solid polymer absorbed approximately 45% by weight of the plasticizer after the Freon 113 had been evaporated while the temperature was raised to 200 C. At this temperature the plasticized polymer was worked manually with a brass rod until it became uniform in composition and appeared transparent and the solid was: then transferred to a hot press where it was molded to yield a resilient piece under a pressure of less than pounds per square inch at a temperatureof around 200 to 210 C.

With .respect to the chemical properties of the hexa- ,fluorobutadien e-1,3 high molecular weight polymer, it may be said that it is relatively inert as formed. The reason for this is, of course, the fact that it is substantially completely fluorine-substituted. Its inertness is somewhat reduced by the presence of double bonds. However, the unsaturation present is much less reactive than that of a {hydrocarbon polymer. .For example, exposure to air for long periods of the perfluorobutadiene high polymer without any added stabilizers against oxidation, has little effect on the fluorocarbon polymer under conditions which quickly destroy all.elastic properties of an unsaturated hydrocarbon polymer unless efiective stabilizers are added. The double bonds may be eliminated by saturating with a fluorinating agent such as elemental fiuorine, antimony pentafiuoride, ClFs, chlorine, or with mixtures of chlorine and fluorine. After fluorine treatment the material resembles hard rubber becoming ,relatively less flexible and elastic while the softening point increases. However, the polymer changes relatively little in its mechanical properties after chlorine treatment and iretains its =resiliency.

The solid plastic high molecular weight hexafluorobutadime-1,3 polymer is useful in many ways. Its elasticity and'high recovery after distortion make it particularly ivaluble ;,a s *a,;gaske t material and .for valve seats. Its .cor-

' the polymer has been fluorinated or chlorinated since after such treatment it is exceedingly stable.

it is useful also in many situations where rubber would be used because of its resiliency. The hexafiuorobutadiene-l,3 polymer, particularly after fluorination or V chlorination, may of course be used in those applica tions where rubber having similar physical properties would fail because of the corrosive conditions.

. It is within the scope of my invention to produce poly mers from other polyunsaturated fluoroolefins such as those disclosed in my co-pending application Serial Number 173,689 (48), filed July 13, 1950, e. g.,

CFCl=CC1-CCl=CF2,

B. P. 104.5 C. at 740 mm. Hg;

CFCl=CClCCl=CFCl,

, B. P. 140.6" C.; CFCI=CFCF=CFC1, B. P. 82.7-83.2

bromine takes the place of chlorine. Copolymers of these monomers may also be prepared. The methods disclosed in this application are useful for preparing such polymers. Under the conditions described for thermal reaction in the foregoing, the following illustrations of copolymerization may be carried out:

- High molecular weight polymers may be made employ- In general,

ing organic peroxides, from mixtures of monomers such as:

The fluorocarbons and their derivatives of this invention are produced from olefins containing no hydrogen but some hydrogen may appear in .the final product as the result of promoter fragments becoming attached to the product. The amount of hydrogen impurity in the product is less than 2% by weight and generally between 0% and 0.5%.

Since many embodiments might be made of the present invention and since many changes might be made in the embodiment described, it is to be understood that the foregoing description is to be interpreted as illustrative only and not in a limiting sense.

I claim:

1. A plastic composition comprising high molecular weight solid polymeric hexafluorobutadiene-l,3 and a low molecular weight liquid polymer of hexafluorobutadime-1,3 as plasticizer.

2. Solid plastic polymeric hexafluorobutadiene-l,3.

3. Solid polymers of a polyunsaturated fluoroolefin i which has at least three and not more than 12 base carbon atoms, at least two double bonds betweenbase carbon atoms, and at least one fluorine atom attached to a base carbon atom, the remaining substituents being selected from at least one of the group consisting of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms.

4. Solid polymers of a compound of the formula which has not more than 12 base carbon atoms per molecule and at least one of the R substituents is fluorine and the remaining R substituents are selected from the group consisting of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms.

5. Solid polymers of a compound of the formula which compound has not more than 12 base carbon atoms per molecule and consists of carbon and halogen, in which at least one of the R substituents is fluorine, at least one R substituent is a perhaloalkyl group of up to three carbon atoms and not more than one R substituent 'isan organic radical containing more than three carbon atoms.

8. Solid polymers of a compound of the formula which compound has not more than 12 base carbon atoms per molecule and consists of carbon and halogen selected from the group consisting of fluorine and chlorine, in which at least one of the R substituents is fluorine and not more than one R substituent is an organic radical containing more than three carbon atoms.

9. Solid polymers of a conjugated butadiene completely substituted by halogens selected from the group consisting of fluorine and chlorine in which at least one of the substituents is fluorine.

10. A solid polymer of hexafluorobutadiene-L3.

11. A solid polymer of dichlorotetrafluorobutadiene- 1,3.

12. Solid polymers of a compound of the formula which has not more than 12 base carbon atoms per molecule and at least one of the R substituents is fluorine and the remaining R substituents are selected from the group consisting of the halogens andperhalogenated organic radicals not more than one of which contains more than three carbon atoms.

13. Solid polymers of a compound of the formula which compound has not more than 12 base carbon atoms per molecule and consists of carbon and halogen, in which at least one of the R substituents is fluorine and not more than one B. substituent is an organic radical containing more than three carbon atoms.

14. Solid polymers of a heXadiene-LS completely substituted by halogen in which at least one of the substituents is fluorine.

15. Solid polymers of a hexadiene-l,5 completely substituted by halogens selected from the group consisting of fluorine and chlorine in which at least one of the substituents is fluorine.

16. A solid polymer of perfluorohexadiene-1,S.

17. The method of producing solid polymers which 1 comprises introducing into a reaction zone and maintaining at a temperature in the range of 90 C. to 700 C., a polyunsaturated fluoroolefin having at least three and not more than 12 base carbon atoms, at least two double bonds between base carbon atoms, and at least one fluorine atom attached to a base carbon atom, the remaining substituents bein gselected from the group consisting of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms, and collecting a solid polymeric material.

18. The method of producing solid polymers which comprises introducing into a reaction zone a compound of the formula of the formula RRC=CR-CR=CRR which compound has not more than 12 base carbon atoms per molecule and consists of carbon and halogen, in which at least one of the R substituents is fluorine and not more than one R substituent is an organic radical containing more than three carbon atoms, maintaining said compound at a temperature in the range of C. to 700 C., and collecting at least one solid polymeric material.

20. The method of producing solid polymers which comprises introducing into a reaction zone a compound of the formula which compound has not more than 12 base carbon atoms per molecule and consists of carbon and halogen selected from the group consisting of chlorine and fluorine, in which at least one of the R substituents is fluorine, and not more than one R substituent is an organic radical containing more than three carbon atoms, maintaining said compound at a temperature in the range of 90 C. to 700 C., and collecting at least one solid polymeric material.

21. The method of producing solid polymers which comprises introducing into a reaction zone hexafluorobutadiene-l,3, maintaining said compound at a temperature in the range of 90 C. to 700 C., and collecting a solid polymer of hexafluorobutadiene-L3.

22. The method of producing solid. polymers which comprises introducing into a reaction zone a compound of the formula which has not more than 12 base carbon atoms per molecule and at least one of the R substituents is fluorine and the remaining R substituents are selected from the group consisting of the halogens and perhalogenated organic radicals not more than one of which contains more than three carbon atoms, maintaining said compound at a temperature in the range of 90 C. to 700 C., and collecting solid polymeric material.

23. The method of producing solid polymers which comprises introducing into a reaction zone and maintaining at a temperature in the range of 90 C. to 700 C., a polyunsaturated fluoroolefin having at least three and not more than 12 base carbon atoms, at least two double bonds between base carbon atoms, and at least one fluorine atom attached to a base carbon atom, the remaining substituents being halogens, and collecting a solid polymer of said polyunsaturated fluoroolefin.

24. The method of producing solid. polymers which comprises introducing into a reaction zone perfluorohexadime-1,5, maintaining said compound at a temperature in the range of 90 C. to 700 C. and collecting at least one solid polymeric material.

References Cited in the file of this patent UNITED STATES PATENTS 2,230,654 Plunkett Feb. 4, 1941 2,406,153 Lewis Aug. 20, 1946 2,567,956 Miller Sept. 18, 1951 2,600,802 Passino June 17, 1952 2,668,182 Miller Feb. 2, 1954 

3. SOLID POLYMERS OF A POLYUNSATURATED FLUOROOLEFIN WHICH HAS AT LEAST THREE NOT MORE THAN 12 BASE CARBON ATOMS, AT LEAST TWO DOUBLE BONDS BETWEEN BASE CARBON ATOMS, AT LEAST ONE FLUORINE ATOM ATTACHED TO A BASE CARBON ATOM, THE REMAINING SUBSTITUENTS BEING SELECTED FROM AT LEAST ONE OF THE GROUP CONSISTING OF THE HALOGENS AND PERHALOGENATED ORGANIC RADICALS NOT MORE THAN ONE OF WHICH CONTAINS MORE THAN THREE CARBON ATOMS. 